A man who worked with Makihisa Tohno to attack the Nanaya clan. He fought Shiki's father Kiri Nanaya. Shiki's childhood memory caused his dream's manifestation of death to appear as Kouma. He is described as the perfect combination of human and demon blood, and possesses massive physical strength and speed, being able to crush trees with his bare hands. His nickname is Red Lion. Like Tohno Akiha is unique in the Tohno bloodline due to the ancient nature of the origins of her demonic powers, Kouma is unique for the degree of purity of the Oni Blood in him. As a result of this he was caged by his own family. Later his family was killed by another Half-Demon family & the head of that family kept him like a guard dog, but Kouma due to his inherent awareness of the dangerous ness of his impulse had suppressed it. When Nanaya Kiri assassinated the head of that family, he had burst Kouma's right eye in a momment of frenzy (It was the first time in his life that he experienced his "Inversion Impulse"). This soonmade Kouma loose control over his impulse & become the monster that he is now. On the night of the attack on Nanayas, while the rest of the attackers were killed by the traps or dispathced by Kiri, only Kouma was unscathed. It was he who kileed Kiri, though he recieved a fatal wound in the process & htus lost total control over his impulse & the massacred the rest of the clan, but failed to kill Shiki as his mother sheilded him while dying in the process. Whether or not Kouma died that night by succumbing to the injury or survived is unknown, but the incident resulted in him becoming Shiki's 2nd greatest fear, the first being Shiki's own "Mystic Eyes of Death Perception". (Source: Wikipedia, Kagetsu Tohya - Ten Nights of Dreams - "Red Demon God")